How to Eliminate Lighting Shadows and Achieve Even Illumination with Commercial LED Lights

Lighting shadows, also called tunneling, occurs when uneven light distribution creates noticeably darker areas between fixtures. This common problem affects both indoor and outdoor lighting installations, from commercial warehouses to parking lots and sports facilities.

Poor lighting distribution doesn’t just look unprofessional. It can create safety hazards, reduce productivity, and waste energy. Whether you’re installing LED parking lot lights or upgrading LED sports field lights, understanding how to prevent shadows ensures your lighting upgrade delivers the performance you expect.

What Are Lighting Shadows?

Shadowing occurs when light levels vary significantly across a space, typically, most bright directly under fixtures and noticeably dimmer between them. Even modest variations in illumination can create a tunnel effect, particularly in applications with lower ceiling heights.

The most common example is office hallways with recessed fixtures. As you walk down the corridor, brightness alternates between well-lit areas under each fixture and darker zones in between.

Poor Distribution: Notice the Dark Areas Between Fixtures

Proper Distribution: Even, Balanced Lighting

4 Primary Causes of Lighting Shadows

1. Excessive Fixture Spacing

When fixtures are spaced too far apart, light cannot adequately overlap between mounting points. This issue becomes more pronounced at lower mounting heights, where beam spread is naturally more limited.

2. Using Fewer High-Output Fixtures Instead of More Moderate-Output Units

Some facility managers attempt to reduce installation costs by using fewer, more powerful fixtures. This approach often creates bright spots under fixtures with noticeably dark areas between them, rather than achieving uniform distribution.

3. Physical Obstructions

Machinery, tall shelving, structural elements, or low-hanging trusses can block light paths and create shadow patterns throughout a space.

4. Incorrect Beam Angle Selection

LED fixtures offer various beam angle options (measured in degrees). Narrow beam angles work well for high-bay applications, while wider beams suit lower mounting heights. Using narrow optics when wider distribution is needed commonly causes shadowing.

Using Lighting Plans to Eliminate Shadows

Professional lighting plans use specialized software to model light distribution and identify potential shadow issues before installation. A comprehensive plan includes:

• Average illumination levels (foot-candles or lux)
• Specific fixture specifications and quantities
• Precise mounting locations and heights
• Beam angle recommendations
• Average-to-minimum illumination ratios

Understanding Average-to-Minimum Ratios

The average-to-minimum ratio compares the brightest areas to the dimmest areas in your space. Lower ratios indicate more uniform lighting. Generally, ratios between 2:1 and 4:1 are considered acceptable for most commercial applications, though specific requirements vary by use case.

Note: Corner areas typically show lower light levels due to their distance from fixtures. Many lighting professionals exclude corner readings when calculating ratios for large open spaces, since corners represent a small percentage of usable floor area.

Common Lighting Plan Mistakes

Even professional lighting plans can fail when implementation doesn’t match the design specifications.

Incomplete Site Information: Failing to communicate obstructions, ceiling height variations, or usage requirements leads to inaccurate plans.

Fixture Substitutions: Switching to different fixtures after the plan is complete typically compromises results. Each plan is designed around specific fixture photometrics; changing fixtures essentially invalidates the entire calculation.

Get Professional Lighting Design Support

LED Lighting Supply provides complimentary lighting plans for commercial and industrial projects. Our team uses professional-grade software to ensure proper light distribution and eliminate shadowing before you purchase fixtures.

We offer free lighting design services to:

• Licensed electrical contractors
• Energy service companies (ESCOs)
• Commercial and industrial end users

Request Your Free Commercial Lighting Plan

Important: All electrical work should be performed by qualified electricians in accordance with local electrical codes and safety requirements. Consult with lighting professionals to ensure your installation meets applicable standards for your specific application.